什么是宏（（无效（*）（））0）（）是什么意思？ [英] What does the macro ((void(*)())0)() mean?

问题描述

以下宏的结果是显而易见的：

The outcome of the following macro is clear:

#define CRASH() do {\
  *(int *)(uintptr_t)0xbbadbeef = 0;\
  ((void(*)())0)();\
} while (false)

我的问题是，什么是行

My question is, what does the line

((void(*)())0)();

分解到，在英语吗？例如，这是返回一个指针....函数

break down to, in English? For example, "this is a function that returns a pointer to a...."

推荐答案

它看起来就像投下 0 作为函数指针（与签名，它需要没有参数，有返回void类型），然后调用它。

It looks like it casts 0 as a function pointer (with the signature that it takes not parameters and has void return type) and then invokes it.

(     (            void(*)()                  ) 0       )      ();
  /* cast..*/ /* fn pointer signature */  /*..cast 0 */  /* invocation */

这是另一种方式说，这是试图调用（呼叫），该公司预计将位于内存地址0x00000000功能 - 这是保证是一个无效的地址

Which is another way to say that it's trying to invoke (call) a function that's expected to be located in memory at address 0x00000000 - which is guaranteed to be an invalid address.

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